New Diesel Engine Integration: Engine Mounting System using Active Vibration Absorber Torque Struts 2006-01-0283
Diesel engines have large input displacements (or forces) at lower rpms. Specifically, these engines exhibit undesirable force/displacement inputs into the vehicle, through the engine mounts, at idle rpms, and off idle rpms in certain driving condition (low rpm condition while vehicle is moving from rest). These undesirable forces can contribute to poor in-vehicle NVH characteristics.
Current market trends, as well as our joint experience with countermeasures to suppress or isolate these inputs, suggest that a bi-state or active engine mount can assist in addressing these high input, low frequency conditions. We will detail how we addressed this condition by implementing an active mount technology, and in the particular form of active torque struts on a French OEM's high-end sedan. These vacuum actuated active mounts were chosen due to their ability to utilize off-the-shelf electrovalves, very low current draw, and the use of vacuum flow rate (an existing supply of energy available on most vehicles; diesels usually have dedicated vacuum pumps). We will examine the attributes of these now production parts, their advantages relative to other active counter measures in the market, and their future potential as a light-weight, cost effective, low fuel consuming technology that could be used to address future NVH issues with diesel, direct inject, cylinder deactivation, hybrid, and other upcoming and current powertrain technology. This application of active technology in engine mounts is a first for the European continent.